Development of a software tool for the evaluation of the shading factor under complex boundary conditions

12th Conference of International Building Performance Simulation Associatio

Моделирование энергопотребления зданий: оценка статической и динамической моделей

The aim of the present paper is to show recent results obtained in modeling the building system, presenting a review on the common numerical models used to estimate the energy consumptions. In particular, both steady-state and dynamic models are investigated by analyzing their main assumptions, limitations and fields of usage. As a matter of fact, the most common models are based on steady state approaches, but new technologies and the need to implement innovative regulation criteria for heating and cooling systems by performing detailed coupled studies on the building and heating/cooling systems, push towards the use of dynamic tools with low computational costs. Therefore, the use of dynamic models is often suggested, especially when different building configurations are investigated (as e. g. in the design stage or for a renovation perspective). Starting from this point, sensitive analyses on the installation of a proper insulation in the building envelope is then presented.Цель данной работы — показать последние результаты, полученные при моделировании системы здания, с описанием общих численных моделей, используемых для оценки энергопотребления. В частности на статических и динамических моделях исследованы основные допущения, ограничения и область использования путем их анализа. Собственно говоря, наиболее распространенные модели основаны на установившихся подходах, но новые технологии и необходимость внедрения для систем отопления и холодоснабжения инновационных критериев регулирования с использованием подробного анализа здания и систем отопления/охлаждения, подталкивают к использованию динамических инструментов с низкими вычислительными затратами. Таким образом, часто целесообразно использование динамических моделей, особенно когда существуют разные конфигурации здания (как, например, в стадии проектирования или для перспективной реконструкции). В статье представлен анализ установки правильного утеплителя в ограждающих конструкциях

Enhancement of the UK Standard Assessment Procedure (SAP) solar water heating prediction algorithm using parametric dynamical thermal simulations

SAP is the UK Government’s method for calculation of a dwelling’s energy efficiency and carbon dioxide emissions. This paper presents a method of informing the SAP procedure regarding evaluation of the advantage given to SAP ratings by installation of typical domestic Solar Domestic Hot Water (SDHW) systems. Comparable SDHW systems were simulated using the dynamic thermal simulation package TRNSYS and results were translated into empirical relations in a form that could be input into the SAP calculation procedure. Findings were compared against the current SAP algorithm and differences explained. Results suggest that calculation variances can exist between the SAP methodology and detailed dynamic thermal simulation methods. This is especially true for higher performance systems that can deviate greatly from default efficiency parameters. This might be due to SAP algorithms being historically based on older systems that have lower efficiencies. An enhancement to the existing SAP algorithm is suggested

Cities and energy:urban morphology and residential heat-energy demand

Our aim is better understanding of the theoretical heat-energy demand of different types of urban form at a scale of 500 m × 500 m. The empirical basis of this study includes samples of dominant residential building typologies identified for Paris, London, Berlin, and Istanbul. In addition, archetypal idealised samples were created for each type through an analysis of their built form parameters and the removal of unwanted ‘invasive’ morphologies. The digital elevation models of these real and idealised samples were run through a simulation that modelled solar gains and building surface energy losses to estimate heat-energy demand. In addition to investigating the effect of macroscale morphological parameters, microscale design parameters, such as U-values and glazing ratios, as well as climatic effects were analysed. The theoretical results of this study suggest that urban-morphology-induced heat-energy efficiency is significant and can lead to a difference in heat-energy demand of up to a factor of six. Compact and tall building types were found to have the greatest heat-energy efficiency at the neighbourhood scale while detached housing was found to have the lowest

3D simulation of complex shading affecting PV systems taking benefit from the power of graphics cards developed for the video game industry

Shading reduces the power output of a photovoltaic (PV) system. The design engineering of PV systems requires modeling and evaluating shading losses. Some PV systems are affected by complex shading scenes whose resulting PV energy losses are very difficult to evaluate with current modeling tools. Several specialized PV design and simulation software include the possibility to evaluate shading losses. They generally possess a Graphical User Interface (GUI) through which the user can draw a 3D shading scene, and then evaluate its corresponding PV energy losses. The complexity of the objects that these tools can handle is relatively limited. We have created a software solution, 3DPV, which allows evaluating the energy losses induced by complex 3D scenes on PV generators. The 3D objects can be imported from specialized 3D modeling software or from a 3D object library. The shadows cast by this 3D scene on the PV generator are then directly evaluated from the Graphics Processing Unit (GPU). Thanks to the recent development of GPUs for the video game industry, the shadows can be evaluated with a very high spatial resolution that reaches well beyond the PV cell level, in very short calculation times. A PV simulation model then translates the geometrical shading into PV energy output losses. 3DPV has been implemented using WebGL, which allows it to run directly from a Web browser, without requiring any local installation from the user. This also allows taken full benefits from the information already available from Internet, such as the 3D object libraries. This contribution describes, step by step, the method that allows 3DPV to evaluate the PV energy losses caused by complex shading. We then illustrate the results of this methodology to several application cases that are encountered in the world of PV systems design.Comment: 5 page, 9 figures, conference proceedings, 29th European Photovoltaic Solar Energy Conference and Exhibition, Amsterdam, 201

The development of a mapping tool for the evaluation of building systems for future climate scenarios on European scale

The paper presents a tool for the mapping of the performance of building systems on European scale for different (future) time periods. The tool is to use for users and be applicable for different building systems. Users should also be able to use a broad range of climate parameters to assess the influence of climate change on these climatic parameters. Also should the calculation time be reasonable short. The mapping tool is developed in MATLAB, which can be used by other users for their own studies.Comment: 21 pages, 24 figures, pre-conferenc

A low cost shading analyzer and site evaluator design to determine solar power system installation area

Shading analyzer systems are necessary for selecting the most suitable installation site to sustain enough solar power. Afterwards, changes in solar data throughout the year must be evaluated along with the identification of obstructions surrounding the installation site in order to analyze shading effects on productivity of the solar power system. In this study, the shading analysis tools are introduced briefly, and a new and different device is developed and explained to analyze shading effect of the environmental obstruction on the site on which the solar power system will be established. Thus, exposure duration of the PV panels to the sunlight can be measured effectively. The device is explained with an application on the installation area selected as a pilot site, Denizli, in Turkey. © 2015 Selami Kesler et al